The described invention relates in general to systems and devices for use in cell culture, and more specifically to a cell culture system and substrate that includes one or more polymer scaffolds adapted to be contained within a bioreactor, wherein the fiber scaffolds further include polymer fibers that have been created by electrospinning, and wherein the orientation of the fibers in the scaffold relative to one another is generally parallel, random, or both.
Certain types of mammalian cells require attachment to a substrate so that they may adequately proliferate and undergo normal cellular function. These cells typically include a variety of stem or progenitor cells such as, for example, mesenchymal stem cells (MSC), and are of interest for a variety of clinical applications and therapies. However, the number of viable cells required for a typical therapeutic dose can be millions or billions per patient. Additionally, stem cells easily differentiate into other undesirable cell types while being expanded in vitro, thereby reducing the efficiency of the expansion process and creating a major problem for stem cell suppliers. Accordingly, there is a significant need for commercially available technologies that are capable of greatly expanding a relatively small number of stem or progenitor cells into a much larger population of such cells while maintaining the pluripotency thereof.
Current commercially used cell expansion processes typically involve large reusable stainless steel or glass bioreactors that must be cleaned and disinfected between batches or disposable, single-use bioreactors that resemble plastic bags. Stem cells are added to these bioreactors with appropriate media and reagents for promoting cell growth and then the bioreactors are closely monitored until a desired concentration of cells is achieved. For adherent cells, porous beads made from polystyrene and other polymers are added into the growth media and cell mixture to allow the cells to attach and grow normally. However, once the desired concentration of cells is achieved it is very difficult to remove all of the cells from the porous beads. This results in a low efficiency of usable cells for the desired end application. Therefore, there is an ongoing need for a cell culture system that permits desired cell growth and proliferation and that allows cultured cells to be harvested efficiently and in large numbers.